katsumi takeda etal



1964 KATSUMI- TAKEDA ETAL. 3,113,274

SUNRISE-AND-SUNSET CONTROLLED TIMEKEEPING DEVICE Filed Feb. 14, 1962 2Sheets-Sheet 1 21, 1964 KATSUML TAKEDA ETAL 3,113,274

SUNRISE-AND-SUNSET CONTROLLED TIMEKEEPING DEVICE Filed Feb. 14, 1962 2Sheets-Sheet 2 United States Patent 3,118,274 SUNRliSE-AND-SUNSETCONTROLLED TIMEKEE'PING DEVICE Katsunri Talreda and Airiteru Kamimoto,both of Fukuyanra, Prefecture of Hiroshima, Japan, assignors toMitsubishi Deniri Kabushiki Kaisha, Tokyo, Japan, a

ccrporation of Japan Filed Feb. 14, 1962, Ser. No. 173,256 Claimspriority, application Japan Feb. 18, 1951 8 Claims. (Cl. 58-23) Thisinvention relates to a sunrise-and-sunset controlled timekeeping device.

It is widely practiced to indicate or determine the hour by using anytimekeeper including a balance wheel or a pendulum or any electrictimekeeper driven by a synchronous motor or the like. However, all typesof timekeepers commonly used are inherently disadvantageous in that theyresult in erroneous indication of the hour due to the effect of dailyrates added to one another during long service.

A general object of the invention is to provide an improved timelreeperdevice wherein the abovementioned disadvantage is eliminated.

An object of the invention is to provide a sunrise-andsunset timekeeperdevice which is controlled by every sunrise and every sunset to providethe basic hour during either daytime or nighttime to eliminate anyerroneous indication of the hour resulting from the integration of dailyrates effected during long service whereby the hour can be nearlycorrectly indicated at any moment.

Another object of the invention is to provide an electric timekeeperdevice which is driven by a synchronous motor and controlledby everysunrise and every sunset to provide the basic hour during daytime andnighttime, and which will automatically recover lost time due tostoppage of electric supply to the motor being operated.

With the objects in View, the invention resides in a timekeeper devicecomprising photoconductive means responsive to both sunrise and sunset,rotatable control means actuated by said photoconductive means to bestarted at either sunrise or sunset, and an hour dial member provided onsaid rotatable means for rotation therewith. The rotatable means isrotated with a ratio of speed of rotation during the daytime to thatduring the nighttime of 1:2 or 2:1 and cooperates with an hourindicating pointer member to indicate the hour at any moment in thenighttime or daytime.

In a preferred embodiment of the invention a timekeeper device comprisesdriving means having a predetermined fixed driving speed, meansresponsive to both the sunrise and the sunset including means forstarting operation of said driving means at the sunrise, speed changingmeans, hour indicator means including a graduated member driven by saiddriving means through said speed changing means. The speed changingmeans is controlled by said sunrise-and-sunset responsive means tochange the angular speed of said graduation member of said hourindicator means for a predetermined magnitude during a time intervalbetween the sunrise and the sunset to twice said predetermined magnitudeduring a time interval between the sunset and the succeeding sunrise.Control means are controlled by the hour indicator means to maintain thedriving means in operation for a period of time for which the drivingmeans is to be operated and to stop operation of said driving means uponthe completion of one revolution of said hour indicator means before thesucceeding sunrise, and an indicating member is provided for cooperatingwith said graduated member of said hour indicator means to indicatenearly correctly the hour at any moment in the nighttime.

The driving means preferably comprises a synchronous dfiil fiid PatentedJan. 21, 19-04 motor adapted to be energized from the commercialalternating current line.

in order to indicate nearly correctly the hour in the daytime, thesynchronous motor may be started to be operated at the sunset and thegraduated member of said hour indicator means is driven at saidpredetermined magnitude of angular speed during the time intervalbetween the sunset and the succeeding sunrise and at twice saidpredetermined magnitude during the time interval between the sunrise andthe sunset respectively.

If the timekeeper device is desired to control a utilization device saidindicating member may preferably be formed as a movable arm of a switchfor controlling the utilization device. In order to activate the switchthe hour indicator means may be provided with at least one notch on saidgraduation member at a position corresponding to the hour at which theutilization device is to be controlled.

The invention will become more readily apparent from the followingexemplary description taken in conjunction with the accompanyingdrawings in which:

FIG. 1 is a typical graph illustrating the sunrise and the sunsetplotted against the calendar month;

FIG. 2 is a diagrammatic view of a timekeeper device constructed inaccordance with the teachings of the invention; and

FIG. 3 is a diagrammatic view of the device of FIG. 2. is operation.

The invention is based upon the discovery that, with reference to anycalendar day, a time interval between the sunrise and 1200 hours isapproximately equal to a time interval between the midday and the sunsetwhile a time interval between the sunset and 0000 hour is approximatelyequal to a time interval between 0000 hour and the succeeding sunrise.

Referring now to P16. 1 of the drawings, there is shown a typical graphillustrating the sunrise and the sunset measured in Kobe, Iapan (whichis in latitude 3441N and in longitude 11E) and plotted against thecalendar month. In FIG. 1 a curve r represents the sunrise and a curve srepresents the sunset. A curve m indicates the hour averaging thesunrise and the sunset and a curve m indicates the hour averaging thesunset and the succeeding sunrise. As shown in FIG. 1, a deviation ofthe curve m from the horizontal line passing through the ordinate of1200 hours is in the same direction as an approximately equal to that ofthe curve m from the horizontal line passing through the ordinate of2400 hours. Such deviations are relatively small in magnitude.Therefore, if it is assumed that, with reference to any calendar day, Trepresents a time interval between the sunrise and 1200 hours, T a timeinterval between 1200 hours and the sunset, T a time interval betweenthe sunset and 0000 hour, and T represents a time interval between 0000hour and the succeeding sunrise then it will be seen from FIG. 1 that Tis approximately equal to T and that T is approximately equal to TTherefore, we have In other words, a half of the sum of the timeinterval between the sunrise and the sunset and the time interval between the sunset and the succeeding sunrise is, at all times,approximately equal to an interval of 12 hours through a year regardlessof the sunrise and sunset.

Referring now to FIG. 2, there is diagrammatically illustrated atimekeeper device embodying the principle of the invention and providingthe basic hour during the nighttime. However, it is to be understoodthat the invention is equally applicable to a timekeeper deviceproviding the basic hour during the daytime.

As shown in FIG. 2, the timekeeper device comprises a sunrise-and-sunsetresponsive unit generally designated by the reference characters SRU, adrive such as a synchronous motor M, a speed changing unit generallydesigmated by the r ference characters SCU and controlled by thesunrise-and-sunset responsive unit SRU, and an hour indicator unit HIUdriven by the synchronous motor M through the speed changing unit SCU.

The sunriseand-sunse' responsive unit SRU includes a photocellcomprising photosensitive cadmium sulfide or the like which has itsinternal resistance variable in response to exposure to light. Thephotocell it is c0nnected to a resistor 12 connected in series to arectifier i i and is also operatively connected to a control relay in.The relay 16 comprises an operating winding 13 connected in series tothe photocell lit, a movable contact member and a pair of stationarycontacts 22. The movable contact member 243 has one end electricallyconnected to the operating winding 13 and the other end normally one ofthe stationary contacts 22 or in this case the lower stationary contactas viewed in FIG. 2. The movable contact member 2b is connected to amovable rod which, in turn is connected to a lever of an electricallyinsulating material as at one end. The lever 26 is supported at itsfulcrum 28 and connected at the other end to a connecting rod 35) aswill be later described. The arrangement comprising the rectifier lid,the resistor E2, the photocell iii and the operating winding 18 seriallyconnected to each other is connected across a source of alternatingcurrent repre ented by a pair of input terminals 32. in order to smooththe rectified output from the rectifier 14 a smoothing capacitor 3 5- isprovided on the output of the rectifier. The lower plate of thecapacitor 34 is directly connected to the operating winding 13 and alsoto the lower input terminal 32.

The synchronous motor M is connected between the upper input terminal 32as viewed in 2 and a transfer arm 33 of a holding switch as. The switch36 includes a pair of stationary contacts ill and i2. The upper contact4-4) is connected to the junction of the capacitor 34 and the operatingwinding 18 of the control relay 16 while the lower contact 32 isconnected to the upper contact member 22 of the relay with the transferarm 33 normally engaging the lower contact 42.

The speed changing unit SCU comprises a transfer gearing generallydesignated by the reference numeral 44 and a reduction gearing generallydesignated by the reference numeral as. The transfer gearing 44 includesa first gear 48 rigidly mounted on a shaft for the motor M, a secondgear 5t) normally meshing a first gear 4% and a third gear 5'2 securedon a shaft 54 for the second gear 52. The third gear 52 is coupledthrough an intermediate gear 56 to a fourth gear 58 secured on a shaft6%. The shaft oil is provided with a fifth gear 62; which is twice aslarge as the first gear 48 in tooth number. As diagrammatically shown inFlG. 2, the shafts 5dand 6t are operatively coupled to the connectingrod 3%) in such a manner that the engagement of the movable contactmember Zil of the control relay 16 with the lower stationary contactmember 22 effects the meshing of the first gear .8 with the second gearand the disengagement of the first gear from the fifth gear 62 whereasthe engagement of the movable contact member with the upper stationarycontact member effects the meshing of the first gear 48 with the fifthgear 62 and the disengagement of the first gear from the second gear.The speed changing unit is also designed and constructed such that whenthe first gear d8 meshes the second gear 5% the intermediate gear 56 isrotated at a speed equal to twice the speed obtained when the first gearmeshes the fifth gear 62.

The reduction gearin 46 includes a pinion 6d integral with theintermediate gear 56 and a gear 66 meshing the pinion 64-.

The hour indicator unit HlU comprises an hour dial 68 rotatable togetherwith the gear so of the reduction more go ring is. The hour dial 68 ispreferably made integrally with the gear 55 and has its front facegraduated in hours throughout one half of the peripheral portionthereof. In the illustrated embodiment the graduation on the hour dial63 includes lmes designated at 20, 21, 22, 23, 0, l, 2, 3 and 4 anddisposed at an angular equidistance corresponding to 22.5 degrees or 1r/8 radian. If desired, the number of the graduated lines and the angulardistance therebetween may be varied.

To indicate the hour an indicating pointer '74) is disposed adjacent tothe periphery of the hour dial 68 at such a position that the pointeraligns with one of the outermost graduated lines or the line 4 in thiscase when the device is not operated.

As shown in PEG. 2, the pointer '79 is formed as a movable arm of acontrol switch 72 and carries a movable contact 74 of the same with itsfree end contacting the peri hery of the hour dial fi The switch 72includes a stationary contact '76. Also the hour dial as is shown ashaving a notch 73 formed on the periphery, for example, at the positionof the graduation line 0. Therefore, it will be seen that during therotation of the hour dial 68 the pointer '70 can drop in the notch 78 toengage the movable contact 74 with the stationary contact 76 to therebyenable the control switch '72 to control a utilization device (notshown).

It is to be understood that more than one of notch may be provided onthe hour dial in accordance with he member of predetermined hours atwhich the utilization device is to be controlled.

lowever, if the timekeeper device will be used only to indicate ormeasure the hour then the switch and notch stru-ct just described may beomitted.

As shown at dotted line in FIG. 2, the hour dial 6% includes further apair of spaced transfer pawls 80 and 32 projecting from the rear facethereof.

Opposite the rear face of the hour dial 28 a control plate of anelectrically insulating material generally designate by the referencenumeral 84 is disposed including on the one end portion a pair of spacedpins 86 and 88 capable of engaging the transfer pawls 80 and 82 oncerespectively during one complete revolution of the hour dial 6%. Thecontrol plate 84 is pivotably mounted substantially at its center on astationary pin 96 and includes on the other end portion of a supportingelement 92 secured to a U- shaped spring 94 at one end which includesthe other end secured to the movable arm 38 of the switch 36 at its freeend. The control plate 84 is further provided with a slot E6 throughwhich a stationary pin 93 extends in order to restrict the pivotalmovement of the control plate.

The device thus far described is operated as follows:

It is now assumed that, before the sunrise the various components of thedevice are in the positions illustrated in HG. 2. As the sky becomeslight at the sunrise the photocell it) internal resistance is abruptlydecreased permitting a current to flow from the source of alternatingcurrent 32 through the operating winding 13 of the control relay 16.Therefore, the operating winding 18 is energized with a rectifiedcurrent from the rectifier 14 which is fed by a source of alternatingcurrent 32,. The energization of the winding 18 effects pulling up ofthe movable contact member 20 to engage the same with the upper contact22 (see FIG. 3). This completes a circuit from the upper input terminal32 through the synchronous motor M, the transfer arm 33 of the holdingswitch 36, the stationary contact 42 thereof, the upper contact 22 ofthe control relay 16 and the movable contact member fit) to the lowerinput terminal 32 to thereby start the operation of the motor.

At the same time, the pulling up of the movable contact member 2t)effects disengagement of the first gear 43 from the second gear 59 andthe engagement of the first gear 43 with the fifth gear 62 through themovable rod 24-, the lever 26 and connecting rod 36 (see PEG. 3).

When the motor M is operated, the hour dial 68 will be rotated in thedirection of the arrow -0 in FIG. 2 through the speed changing unit SCU.It is here to be noted that the hour dial is designed to be rotated atan angular velocity of or 11'/ 16 radians per hour by properly selectingthe speed of the motor M and the gear ratios of the speed changing unitSCU. Soon thereafter, rotation of the motor M, and hence the hour dial68, has been initiated and the transfer pawl 80 on the hour dial forcesthe pin 36 on the control plate 84 to move the plate from its positionillustrated in FIG. 2 to its position illustrated in FIG. 3. Thereby thetransfer arm 38 of the holding switch 36 is separated from the lowercontact 42 and brought into and held in contact with the upper contact40 by the action of the U-shaped spring 94. Thus a holding circuit forthe motor M has been completed. Under these circumstances, therefore,the motor continues to be operated regardless of the deenergization ofthe control relay 16.

As previously described, a half of the sum of the time interval betweenthe sunrise and sunset and the time interval between the sunset and thesucceeding sunrise is, at all times, approximately equal to the intervalof 12. hours throughout a year regardless of the sunrise and sunset. Itwill be apparent that the hour dial 58 has been rotated through an angleof during the period of from the sunrise to the sunset or the period ofT +T =2T That angle is equal to one through which the hour dial isrotated at twice the angular velocity as previously determined for Thours.

At the sunset the photocell 10 is abruptly increased in its internalresistance to deenergize the control relay 16. The deenergization of thecontrol relay effect the separation of the movable contact member 20from the upper contact 22 and the engagement of the contact 20 with thelower contact 22 as Well as the disengagement of the first gear 48 fromthe fifth gear 62 and the engagement of the first gear with the secondgear 50. Because of the presence of the holding circuit the motor M iscontinued to be operated and the hour dial 68 is also continued to berotated at twice said angular velocity or at an angular velocity of (orequal to 22.5") per hour due to the meshing the first gear 48 with thesecond gear 50 until the latter will be rotated through This means thatapproximately 0000 hour is obtained at the time the hour dial which wasinitiated to be rotated at the sunrise has been rotated through an angleof 270 or 31/2 radians. In other words, the device provides the basichour at the instant the hour dial 68 has been rotated through threeright angles.

At 0000 hour the pointer 70 will align with the graduated line 0 on thehour dial 68.

After 0000 hour the hour dial is continued to be rotated at the angularvelocity of 22.5 per hour and the position of the pointer relative ofthe graduation on the hour dial indicates nearly correctly the hour atany moment.

At the instant the hour dial has been rotated through one completerevolution to return back to its starting position or at the instant thepointer 70 has again aligned with the graduated line 4, the transferpawl 82 on the hour dial will force the pin 88 to return the controlplate 84 to its original position illustrated in FIG. 2 incounterclockwise direction as viewed in the same figure through theaction of the U-shaped spring 94. This permits the transfer arm 38 ofthe holding switch 36 to be separated from the upper contact 40 and tocontact the lower contact 42. At that time the control relay 16 hasalready been deenergized to separate the movable contact member 20 fromthe upper contact 22 so that the motor M is stopped. In other words, thehour dial 68 whose operation has been initiated at the sunrise isstopped at 0400 hours.

From the foregoing it will be appreciated that, because the hour dial isgraduated at intervals of 225 and that the same is rotated at an angularvelocity of 225 per hour after the sunset, the position of the pointerrelative to the hour dial indicates nearly correctly the hour at anymovement after the sunset.

According to the invention any stoppage of electric supply to the motorwhich is in operation can be compensated for by utilizing a period offrom 0400 hours to the sunrise for which the hour dial is stationary.For example, if it is assumed that electric supply to the motor has beeninterrupted for an interval of three hours beginning at 2200 hours thenthe pointer will align with the graduated line 1 on the hour dial whenthe actual hour is 0400 hours. Accordingly the motor will be continuedto be operated until the sun will rise for example at 0500 hours. Afterthe sunrise the motor is continued to be operated in the manner aspreviously described. Therefore, a time lag of the indication of thepointer due to the stoppage of electric power can be compensated forpartially, namely by an interval of one hour beginning at 0400 hours andterminating at 0500 hours. Thus it will be appreciated that the time lagreferred to can be fully compensated during three days.

While the invention has been described in terms of a timekeeper devicedesigned to provide the basic hour in the night time it is equallyapplicable to a timekeeper device designed to provide the basic hour inthe daytime. In the latter case, the motor will be started to beoperated at the sunset and the hour dial will have its angular velocityin the daytime equal to twice the angular velocity thereof in thenighttime. In this manner the device provides the basic hour at 1200hours and indicates nearly correctly the hour at any moment in thedaytime.

From the foregoing it will be appreciated that the objects of inventionhave been accomplished by the provision of a timekeeper devicecomprising sunriseand-sunset responsive means and an hour dialcontrolled by said responsive means and having its angular velocity inthe nighttime equal to twice the angular velocity thereof in the daytimeor vice versa.

While the inevntion has been described in conjunction with the preferredembodiments thereof it is to be understood that various changes indetail of the construction and the combination and arrangement of thecomponents may be resorted to without departing from the spirit andscope of the invention.

What we claim is:

1. In a timekeeping device, in combination, photoconductive meansresponsive to both the sunrise and the sunset, rotatably driven meanscontrolled by said photoconductive means and startable at sunrise, anhour dial member provided on said rotatably driven means for rotationtherewith, means for driving said rotatably driven means in operation ata predetermined angular velocity during the daytime and at twice saidpredetermined angular velocity during the nighttime and an hourindicating pointer member cooperative with said hour dial member toindicate the hour at any moment at least in the nighttime.

2. in a timekeeping device, in combination, photoconductive meansresponsive to both the sunrise and the sunset, rotatably driven meanscontrolled by said photoconductive means and startable at sunset, and anhour dial member provided on said rotatably driven means for rotationtherewith, means for driving said rotatably driven means in operation ata predetermined angular velocity during the nighttime and at twice saidpredetermined angular velocity during the daytime, and an hourindieating pointer member cooperative with said hour dial member toindicate the hour at any moment in the daytime.

3. A timekeeping device comprising driven means having a predeterminedfixed driving speed, means responsive to both the sunrise and the sunsetincluding means for starting operation of said driving means at thesunrise, speed changing means, hour indicator means including agraduated member driven by said driving means througl said speed chaning means, said speed changing means being controlled by saidsunrise-and-sunset responsive 168118 to change the angular speed of saidhour indicator of said hour indicator means from a predeterminedmagnitnde during a time interval between the sunrise and the sunset totwice said predetermined magnitude during a time interval between thesunset and the succeeding sunrise, control means controlled by said hourindicator means to maintain said driving means in operation for a periodof time for which driving means is to be operated and to stop operationof said driving means upon completion of one revolution of said hourindicator means befor said succeeding sunrise, and an indicating membercooperating with said graduated member of said hour indicator means toindicate substantially correctly the hour at any moment in thenighttime.

4. A timekeeping device comprising driving means having a predeterminedfixed driving speed, means responsive to both the sunrise and the sunsetincluding means for starting the operation of said driving means at thesunset, speed changing means, hour indicator means including a graduatedmember driven by said driving means through said speed changing means,said speed changing means being controlled. by said sunrise-and-sunsetresponsive means to change the angular speed of said graduated member ofsaid hour indicator means from a predetermined rnngnitude during a timeinterval between the sunset and the succeeding sunrise to twice saidpredetermined magnitude during a time interval between the sunrise andthe sunset, control means controlled by said hour indicater means tomaintain said driving means in op ration for a period of time for whichsaid driving means is to be operated and to stop operation of saiddriving means upon the completion of one revolution of said hourindicator means before the succeeding sunset, and an indi cating membercooperating with said graduated member of said time indicating means toindicate nearly correctly the hour at any moment in the daytime.

5. A timekeeping device as claimed in claim 3, wherein aid driving meanscomprises a synchronous motor, and connections for applying alternatingcurrent to said motor.

6. A timekeeping device as claimed in claim 4, wherein said drivingmeans comprises a synchronous motor and connections for applyingalternating current to said motor.

7. A timekeeping device as claimed in claim 3, comprising a controlswitch, said indicator member comprising a movable arm in said controlswitch and wherein said member is provided with at least one notch in aposition in which said indicating member engages said notch at apredetermined hour at which said control switch is to be operated.

8. A timekeeping device as claimed in claim 4, comprising a controlswitch, said indicator member comprisinga movable arm of said controlswitch and said graduated member is provided with at least one notch ina position in which said indicating member engages said notch at apredetermined hour at which the control switch is to be operated.

References tilted in the file of this patent UNITED STATES PATENTS2,446,450 Ziegler Aug. 3, 1948

1. IN A TIMEKEEPING DEVICE, IN COMBINATION, PHOTOCONDUCTIVE MEANSRESPONSIVE TO BOTH THE SUNRISE AND THE SUNSET, ROTATABLY DRIVEN MEANSCONTROLLED BY SAID PHOTOCONDUCTIVE MEANS AND STARTABLE AT SUNRISE, ANHOUR DIAL MEMBER PROVIDED ON SAID ROTATABLY DRIVEN MEANS FOR ROTATIONTHEREWITH, MEANS FOR DRIVING SAID ROTATABLY DRIVEN MEANS IN OPERATION ATA PREDETERMINED ANGULAR VELOCITY DURING THE DAYTIME AND AT TWICE SAIDPREDETERMINED ANGULAR VELOCITY DURING THE NIGHTTIME AND AN HOURINDICATING POINTER MEMBER COOPERATIVE WITH SAID HOUR DIAL MEMBER TOINDICATE THE HOUR AT ANY MOMENT AT LEAST IN THE NIGHTTIME.